Latch needle knitting machines

ABSTRACT

The latch opener is in the form of a feelerlike member which is pointed and directed laterally of a needle. A wedge-shaped blade is inserted into the bent over point of the feelerlike member and is insulated therefrom. The blade forms an electrical connection by way of a wire upon contacting a latch. Engagement of a needle shank on the opposed side of the feeler member does not create an electrical circuit for stopping the machine. Alternatively the body of the feelerlike member can provide the electrical connection with an errant latch. The point of the feelerlike member is coated with or formed of an electrically insulative material.

United States Patent [72] Inventors PeterM. Findlay [54] LATCH NEEDLEKNITTING MACHINES 6 Claims, 7 Drawing Figs.

[52] U.S. Cl 66/111, 66/165 [51] int. Cl 15/08, D04b 35/18 [50] FieldofSearch 66/157, 165, 111

Primary ExaminerWm. Carter Reynolds Attorney-Kenyon & Kenyon Reilly Carr& Chapin ABSTRACT: The latch opener is in the form of a feelerlikemember which is pointed and directed laterally of a needle. Awedge-shaped blade is inserted into the bent over point of thefeelerlike member and is insulated therefrom. The blade forms anelectrical connection by way of a wire upon contacting a latch.Engagement of a needle shank on the opposed side of the feeler memberdoes not create an electrical circuit for stopping the machine.Alternatively the body of the feelerlike member can provide theelectrical connection with an errant latch. The point of the feelerlikemember is coated with or formed of an electrically insulative material.

Pmamium 41922 3.631.890

SHEET 1 OF 2 uxye/v-rom PETER MICHAEL Fl ma RAYMOND HENRY PHILLIPS E 4"OR/YE Y5 LATCH NEEDLE KNITTING MACHINES This invention is forimprovements in latch needle knitting machines and is concerned with animprovement in or modification of the invention described and claimed inU.S. Pat. No. 3,397,556 issued Aug. 20, 1968. The said earlier inventionis concerned with the provision of a combined latch detector andlatch-opening device which at certain times is arranged to detect thepresence of a wrongly positioned needle latch and initiate a signal toeffect stoppage of the machine, and at other times to operate so as toopen closed latches without stopping the machine. The device disclosedas an embodiment of said earlier invention comprises a pointedfeelerlike member which is so shaped that it can enter into the smallspace between a closed latch and the stern of its needle just below thehook and which is so positioned as to be in registry with such space inrespect of all needles which are at a predetermined height at theposition at which the detector device encounters them. In said earlierdevice the feelerlike member is electrically energized for itsfault-detecting function and when so operating will make electricalcontact with a latch not held open by yarn because of a fault and socomplete an electric circuit for stopping operation of the machine. Whenfunctioning as a latch opener the feeler device has its electricalcircuit disconnected so that no electrical impulse will be given when itengages a closed latch specifically for the purpose of opening it.

It has been found in practice that under certain conditions, andparticularly with high-speed working, the precise positioning of thefeelerlike member of the detector device needed to permit it to performthe functions aforementioned does not enable it when operating as afault detector to be kept entirely free from risk of being engaged bystem portions of needles immediately below their hooks for example byreason of some needles tending to lean outward to a slight extent.Consequently with the said earlier construction there is in suchcircumstances a tendency for the machine to be stopped unnecessarily dueto contact of the feelerlike member with the needle stems when in factno faulty latch positioning is present. The invention seeks to reduce oreliminate the tendency for unnecessary stoppage being caused to occur.

In accordance with the invention there is provided in a latch needleknitting machine having a latch opener for performing the two functionsof (a) opening the latches and (b) detecting a fault consisting of amisplaced latch, means whereby the latch opener when operating as afault detector is caused to initiate a signal for effecting stoppageonly when the latch opener becomes engaged with a misplaced latch (andnot if the latch opener becomes engaged with a needle stem or otherpart). To this end the latch opener may have only that part of it whichcan engage with a misplaced latch operative as an electrical contactwhich is connected in a circuit by means of which stoppage of themachine is initiated.

In a convenient form of construction the latch opener is in the form ofa feelerlike member which is pointed and directed laterally of a needleso as to be engageable in the space between a closed latch and thefacing portion of the needle stem under the hook and in which anelectric contact which is insulated from the remainder of the feelerlikemember is positioned on the latch-engaging side only of the feelerlikemember. Thus even through the opposite portion of the feelerlike membermay engage with a needle stem it will not by so doing complete anelectrical circuit for stopping the machine.

A convenient form of construction in accordance with the invention andsome modifications thereof are illustrated by way of example in theaccompanying drawings and will not be described with reference to thedrawings in which FIG. 1 is a perspective view showing the latch openerin working relation to latch needles in a circular knitting machineparts of which are also shown;

FIG. 2 is a side view on a larger scale of the blade of the latchopener;

FIG. 3 is a sectional view on the line IIIIII in FIG. 2;

FIG. 4 is a perspective view of part of a latch opener of modified form;

FIg. 5 is view in cross section taken on the line VV in FIG. 4; and

FIGS. 6 and 7 are perspective views showing other alternative forms ofthe latch opener.

FIGS. 2 and 3 show a latch control member 1 in accordance with thisinvention made up of a wedge-shaped blade 1a and a main body part havinga substantially right-angled bent over pointed end lb. The blade la isfixed into the bent over pointed end lb of the member 1 by means of anonconductive fixing adhesive such as ARALDITE," this being necessary inorder to insulate the two parts electrically from each other. In thisspecific embodiment a piece of finely knitted nylon 1d, isnonconductive, is first pushed into slot lc on the underside of thepoint lb so that it lies around the total internal surface of the slot,and ARALDITE" is then put inside the nylon on the slot followed by thetop edge of blade 1a. In this way it is possible to ensure that theadhesive is evenly distributed between the blade and the point of themember, since it percolates easily through the mesh of the knittednylon, thereby ensuring good electrical insulation between the saidparts.

Other ways of making this latch control member are possible. One shownin FIGS. 4 and 5 is to make the main body 11 of the member out of anonconductive material such as nylon, which, mainly due to the smallsize of the member, still requires that ARALDITE or another form ofadhesive fixer be used to hold the wedge-shaped blade la, but in this instance the slot itself can locate the blade in position without anylining material.

In another alternative form shown in FIG. 6 the point of a conductivemain body of the latch opener 13 is covered with a hard nonconductivematerial 12 such as aluminum oxide to insulate it from electricalcontact with a needle shank. In this form a wedge-type blade is notnecessary, the inside face of the uncovered portion of the latch opener13, adjacent to the tip serving to make electrical contact with amisplaced latch, for fault detection. As the tip of the point is thenearest part of the member to the needles this is the only part liableto touch the needle shank. Therefore the amount of the point covered bythe ceramic need only be very small. Because of this it is possible asin FIG. 7 to replace about one-eighth inch of the end of the point ofthe latch opener 13 with sapphire as at 14 which is nonconductive, orthe part 14 may be a metal tip which is insulated from the remainder ofthe latch detector 13.

The mounting and energization of the latch opener are very similar tothose of the aforesaid earlier construction. Thus in the constructionillustrated the stern 1e of the latch opener is fixed in a block 5pivotally mounted on a post 4 secured to a bedplate 15 of the knittingmachine. The main arm of the latch opener is insulated from the step 1eby an insulating connecting block 16 and it is yieldably urged into theoperative position by a spring 6. Soldered to the back edge of blade lais a wire 3 having an insulating covering which runs along the arm 1 andis connected to the block 5 thence through spring 6, insulated terminaltag 17, wire 18 and electrical circuitry to the stopping means of themachine. Thus, upon contact of the blade with a malfunctioning latch thestopping means will be operated to cut off the electrical supply to thedrive of the knitting machine. The terminal tag 17 is mounted andinsulated from a post fixed to the bedplate 15 which is shown fixed to apillar 19.

In FIG. 1 there is shown the general arrangement of the detector devicewith respect to the needles 2, with the latch opener and control member1 set for operation at a position in the needle circle where the latches2a of the needles 2 are normally held open by the knitted loops aroundthe needle stems. The point of the latch control member 1 is set toproject into the area just below the hook 2b of a raised needle abovethe normal latch guard 21 so that the insides of latches not held openwill engage and make electrical contact with the wedgeshaped blade Ia toeffect a stoppage of the machine. Such setting is effected by means ofan adjustable stop screw 20 passing through and screwed into a lug 5a onthe block 5 to abut against the post 18a under the action of spring 6.

When the latch control member is used as a latch opener, the point ofthe member 1 enters just below the hook 2b of the needle and the bladela engages and earns open the needle latches 2a without operating thestopping means.

To enable the latch control member 1 to be operated as a latch opener,provision is for deenergizing the electrical circuit of the blade la ora circuit controller thereby during certain periods of knitting, such aswhen starting a stocking on bare needles after casting off the previousstocking. Provision is conveniently also made for moving the latchcontrol member out of operative position and away from the needlesduring certain other periods, such as when transferring to make a turnedwelt. For the later purpose there may be pivoted on the bottom part ofpivot post 4 a flat lever 22 acted on by return spring 24 andcooperating with a depending finger or post 23 on lug 5a of block 5. Thelever 22 is coupled to a Bowden cable 25 having its sheath 26 adjustablyfixed to a bracket 27 fixed to the bedplate 15. When the Bowden cable 25is operated from an appropriate control on the knitting machine it willrock the lever 22 clockwise as seen in FIG. 1 to pick up and turn theblock 5 so as to rock the latch opener and control member 1 away fromthe needles 2.

The latch modified latch opener 11 of FIG. 4 can obviously be mountedand connected up exactly as is the latch opener 1 in FIG. 1. The latchopeners 13 of FIGS. 6 and 7 can be mounted in like manner but do notneed the connecting wire 3 since electrical connection to the block 5can be made directly through their stems.

What we claim is:

1. In stop motion apparatus of a latch needle knitting machine, thecombination comprising a latch opener, means for mounting said latchopener on a machine for cooperation with needle latches thereof foropening any that are at least partly closed, electrical signal-sendingmeans associated with the latch opener to produce a machine stop signalwhen the latch opener encounters a closed or partly closed latch, andcontrol means for preventing production of such a signal when latchopening without machine stoppage is required, said signal-sending meansincluding a contact means on the latch opener and exposed to engagementwith a misplaced latch but incapable of contacting other needle parts,said latch opener being in the form of a feelerlike member which ispointed and for latch-opening and fault-detecting purposes is directedlaterally of a needle so as to be engageable in the space between aclosed latch and the facing portion of the needle stem under the hook,and including insulating means thereon insulating that part thereofexposedto possible contact with the needle stem electrically from saidcontact means engageable with a misplaced latch.

2. A combination as claimed in claim 1, wherein the contact means isprovided only on that part of the latch opener which can engage with amisplaced latch.

3. A combination as claimed in claim 1 further having a separateelectrical contact forming said contact means positioned on thelatch-engaging side of said feelerlike member and mounting means forsaid contact forming said insulating means.

4. A combination as claimed in claim 3 wherein the said electric contactis of wedgelike form to converge towards the pointed end of thefeelerlike device and is positioned in a slot therein.

5. A combination as set forth in claim I wherein said pointed end ofsaid feelerlike member which is exposed to possible contact with thestem parts of needles is formed of electrical insulating material.

6. A combination as claimed in claim 1 wherein said pointed end of thefeelerlike member which is exposed to possible contact with the stemparts of needles is electrically insulated from the remainder of saidfeelerlike member.

1. In stop motion apparatus of a latch needle knitting machine, thecombination comprising a latch opener, means for mounting said latchopener on a machine for cooperation with needle latches thereof foropening any that are at least partly closed, electrical signal-sendingmeans associated with the latch opener to produce a machine stop signalwhen the latch opener encounters a closed or partly closed latch, andcontrol means for preventing production of such a signal when latchopening without machine stoppage is required, said signal-sending meansincluding a contact means on the latch opener and exposed to engagementwith a misplaced latch but incapable of contacting other needle parts,said latch opener being in the form of a feelerlike member which ispointed and for latch-opening and fault-detecting purposes is directedlaterally of a needle so as to be engageable in the space between aclosed latch and the facing portion of the needle stem under the hook,and including insulating means thereon insulating that part thereofexposed to possible contact with the needle stem electrically from saidcontact means engageable with a misplaced latch.
 2. A combination asclaimed in claim 1, wherein the contact means is provided only on thatpart of the latch opener which can engage with a misplaced latch.
 3. Acombination as claimed in claim 1 further having a separate electriccontact forming said contact means positioned on the latch-engaging sideof said feelerlike member and mounting means for said contact formingsaid insulating means.
 4. A combination as claimed in claim 3 whereinthe said electric contact is of wedgelike form to converge towards thepointed end of the feelerlike device and is positioned in a slottherein.
 5. A combination as set forth in claim 1 wherein said pointedend of said feelerlike member which is exposed to possible contact withthe stem parts of needles is formed of electrical insulating material.6. A combination as claimed in claim 1 wherein said pointed end of thefeelerlike member which is exposed to possible contact with the stemparts of needles is electrically insulated from the remainder of saidfeelerlike member.